US20060011897A1 - Memory resistance film with controlled oxygen content - Google Patents
Memory resistance film with controlled oxygen content Download PDFInfo
- Publication number
- US20060011897A1 US20060011897A1 US11/226,998 US22699805A US2006011897A1 US 20060011897 A1 US20060011897 A1 US 20060011897A1 US 22699805 A US22699805 A US 22699805A US 2006011897 A1 US2006011897 A1 US 2006011897A1
- Authority
- US
- United States
- Prior art keywords
- oxygen
- manganite
- resistance
- rich
- region
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
- G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
- G11C13/0007—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements comprising metal oxide memory material, e.g. perovskites
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M23/00—Apparatus for adding secondary air to fuel-air mixture
- F02M23/04—Apparatus for adding secondary air to fuel-air mixture with automatic control
- F02M23/06—Apparatus for adding secondary air to fuel-air mixture with automatic control dependent on engine speed
- F02M23/062—Secondary air flow cut-off at low speed
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M23/00—Apparatus for adding secondary air to fuel-air mixture
- F02M23/02—Apparatus for adding secondary air to fuel-air mixture with personal control, or with secondary-air valve controlled by main combustion-air throttle
- F02M23/03—Apparatus for adding secondary air to fuel-air mixture with personal control, or with secondary-air valve controlled by main combustion-air throttle the secondary air-valve controlled by main combustion-air throttle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
- F02M35/10—Air intakes; Induction systems
- F02M35/104—Intake manifolds
- F02M35/108—Intake manifolds with primary and secondary intake passages
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/01—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate comprising only passive thin-film or thick-film elements formed on a common insulating substrate
- H01L27/016—Thin-film circuits
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
- H10N70/011—Manufacture or treatment of multistable switching devices
- H10N70/041—Modification of the switching material, e.g. post-treatment, doping
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
- H10N70/20—Multistable switching devices, e.g. memristors
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
- H10N70/801—Constructional details of multistable switching devices
- H10N70/821—Device geometry
- H10N70/826—Device geometry adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
- H10N70/801—Constructional details of multistable switching devices
- H10N70/881—Switching materials
- H10N70/883—Oxides or nitrides
- H10N70/8836—Complex metal oxides, e.g. perovskites, spinels
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
- F02D2009/0201—Arrangements; Control features; Details thereof
- F02D2009/0244—Choking air flow at low speed and load
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C2213/00—Indexing scheme relating to G11C13/00 for features not covered by this group
- G11C2213/30—Resistive cell, memory material aspects
- G11C2213/31—Material having complex metal oxide, e.g. perovskite structure
Definitions
- This invention generally relates to integrated circuit (IC) memory resistor cell arrays and, more particularly, to an oxygen content system for controlling memory resistance properties in a memory resistor cell and a method for fabricating the same.
- IC integrated circuit
- memory cells using a memory resistor material such as colossal magnetoresistance (CMR) materials
- CMR colossal magnetoresistance
- the CMR material can be said to have a non-volatile nature, as the resistance of the CMR material remains constant under most circumstances. However, when a high electric field induces current flow through the CMR material, a change in the CMR resistance can result.
- the resistivity of the memory resistor at the high field region near the electrode changes first. Experimental data shows that the resistivity of the material at the cathode, referred as terminal A, is increased while that at the anode, referred as terminal B, is decreased.
- the pulse polarity is reversed. That is, the designation of cathode and anode are reversed. Then, the resistivity of the material near terminal A is decreased, and the resistivity near terminal B is increased.
- the present invention describes a thin film resistance memory device suitable for non-volatile memory array and analog resistance applications.
- the present invention memory cell can be reliably programmed, even if fabricated as a resistive non-volatile ultra small size memory cell, because of its asymmetrical characteristics.
- a method for controlling the resistance properties in a memory material.
- the method comprises: forming manganite; annealing the manganite in an oxygen atmosphere; controlling the oxygen content in the manganite in response to the annealing; and, controlling resistance through the manganite in response to the oxygen content.
- the manganite is a material selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5.
- controlling the oxygen content in the manganite includes forming an oxygen-rich RE 1-x AE x MnO y region where y is greater than 3. A low resistance results in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite includes forming an oxygen-deficient RE 1-x AE x MnO y region where y is less than 3. A high resistance is formed in the oxygen-deficient manganite region. More specifically, the process forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. For example, the oxygen-rich manganite region may overlie the oxygen-deficient manganite region.
- the method further comprises: applying a pulsed electric field to the manganite; and, changing the overall resistance through the manganite in response to the pulsed electric field. More specifically, changing the overall resistance through the manganite in response to the pulsed electric field includes: changing the resistance in the oxygen-deficient manganite region; and, maintaining a constant resistance in the oxygen-rich manganite region.
- FIGS. 1A and 1B are partial cross-sectional views of a memory cell during programming ( FIG. 1A ) and erasing ( FIG. 1B ) operations.
- FIGS. 2A and 2B are partial cross-sectional views of a memory cell, where the memory resistor has a cylindrical shape and is embedded in oxide or any suitable insulator.
- FIG. 3 is partial cross-sectional view of the present invention memory resistance film with controlled oxygen content.
- FIG. 4 is a partial cross-sectional view of the present invention memory cell with controlled oxygen content.
- FIGS. 5 a and 5 b are partial cross-sectional views of the memory cell of FIG. 4 during programming and erasing operations, respectively.
- FIGS. 6 through 9 are diagrams of AES data for four memory resistors.
- FIG. 10 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory material.
- FIG. 11 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory resistor or memory cell.
- FIGS. 1A and 1B are partial cross-sectional views of a memory cell during programming ( FIG. 1A ) and erasing ( FIG. 1B ) operations.
- the top and bottom electrodes are identical and the memory resistance material is uniform throughout. If the geometric structure of the device could be made perfectly symmetrical, the net resistance would remains constant, in a high-resistance state, when either a negative field ( FIG. 1A ) or a positive field ( FIG. 1B ) is applied. In such circumstances, programming is not possible. Therefore, a perfectly symmetrical device structure, such as one in FIGS. 1A and 1B , is not practical.
- the geometrically symmetrical memory cell has a high current density near the electrodes (regions A and B), and a low current density in the center portion of the device, in the presence of an electric field.
- the resistivity of the CMR material near the top and bottom electrodes is changed.
- the memory cell can be programmed to be in the high-resistance state if the resistivity of the memory resistor material near the top electrode is increased, and the resistivity of memory resistor material near the bottom electrode is decreased.
- region A and region B are very close to the top and bottom electrode, respectively, and their thicknesses may be as thin as a 10 nanometers (nm), the above-described effect may be mistakenly classified as an interface effect.
- memory is not an interface property change, but is a bulk resistivity change.
- FIGS. 2A and 2B are partial cross-sectional views of a memory cell, where the memory resistor has a cylindrical shape and is embedded in oxide or any suitable insulator.
- the field intensity is high near both top and bottom electrodes. Since the field direction near the top electrode is opposite that near the bottom electrode, the resistivity of the memory resistor material near the top electrode is increased while the resistivity of the memory resistor material near the bottom electrode is reduced. As a result, the memory resistance is programmed to the high-resistance state regardless of whether a positive or negative pulse is applied to the top electrode. Again, a geometrically symmetrical structure is not suitable for resistor memory cell.
- FIG. 3 is partial cross-sectional view of the present invention memory resistance film with controlled oxygen content.
- the film 300 comprises an oxygen-deficient manganite region 302 and an oxygen-rich manganite region 304 , adjacent the oxygen-deficient manganite region 302 .
- the oxygen-rich manganite region 304 overlies the oxygen-deficient region 302 .
- the oxygen-deficient manganite region 302 may overlie the oxygen-rich manganite region 304 .
- the oxygen-rich manganite region 304 is selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5, and y being greater than 3.
- the oxygen-deficient manganite region 302 is selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where y is less than 3.
- the oxygen-rich manganite region 304 has a resistance, less than the resistance of the oxygen-deficient manganite region 302 . Together, the oxygen-rich and oxygen-deficient manganite regions 304 / 302 have an overall first resistance responsive to a negative electric field. The oxygen-rich and oxygen-deficient manganite regions 304 / 302 have an overall second resistance, less than the first resistance, responsive to a positive electric field.
- field direction direction is defined from the perspective of the oxygen-rich manganite region 304 , assuming that the oxygen-rich region 304 overlies the oxygen-deficient region 302 , as shown in FIG. 3 .
- the negative direction is from the oxygen-deficient region 302 to the oxygen-rich region 304 .
- the positive direction is defined herein as being from the oxygen-rich region 304 to the oxygen-deficient region 302 .
- the oxygen-rich and oxygen-deficient manganite regions 304 / 302 have a first resistance in the range of 100 ohms to 10 megaohms (Mohms), in response to a first, negative pulsed electric field having a field strength in the range of 0.1 megavolts per centimeter (MV/cm) to 0.5 MV/cm and a time duration in the range from 1 nanosecond (ns) to 10 microseconds ( ⁇ s).
- MV/cm megavolts per centimeter
- ⁇ s microseconds
- the oxygen-rich and oxygen-deficient manganite regions 304 / 302 have a second resistance in the range of 100 ohms to 1 kilo-ohm (kohm) in response to a second, positive pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 ⁇ s.
- the two manganite regions 302 and 304 have different resistance properties, to insure the asymmetrical characteristics of the film 300 .
- the oxygen-deficient manganite region 302 changes resistance in response to an electric field.
- the oxygen-rich manganite region 304 maintains a constant resistance in response to an electric field.
- the oxygen-rich manganite region 304 has a thickness 306 in the range of 20 to 150 nanometers (nm).
- the oxygen-deficient manganite region 302 can have a thickness 308 in the range of 20 to 150 nm.
- the oxygen-deficient manganite region 302 has a thickness 308 within 0.5 to 1.5 the thickness 306 of the oxygen-rich manganite region 304 .
- FIG. 4 is a partial cross-sectional view of the present invention memory cell with controlled oxygen content.
- the cell 400 comprises a bottom electrode 402 and an oxygen-deficient manganite region 404 overlying the bottom electrode 402 .
- An oxygen-rich manganite region 406 is adjacent the oxygen-deficient manganite region 404 and a top electrode 408 overlies the oxygen-rich manganite region 406 and oxygen-deficient manganite region 404 .
- the oxygen-rich manganite region 406 overlies the oxygen-deficient region 404 .
- the oxygen-deficient manganite region 404 may overlie the oxygen-rich manganite region 406 .
- the oxygen-rich manganite region 406 is selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5, and y being greater than 3.
- the oxygen-deficient manganite region 404 is selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where y is less than 3.
- the top electrode 408 is a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir.
- the bottom electrode 402 is a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir.
- the top electrode 408 need not necessarily be the same material as the bottom electrode 402 .
- the oxygen-rich manganite region 406 has a resistance, less than the resistance of the oxygen-deficient manganite region 404 . Together, the oxygen-rich and oxygen-deficient manganite regions 406 / 404 have an overall first resistance responsive to a negative electric field. The oxygen-rich and oxygen-deficient manganite regions 406 / 404 have an overall second resistance, less than the first resistance, responsive to a positive electric field.
- the oxygen-rich and oxygen-deficient manganite regions 406 / 404 have a first resistance in the range of 100 ohms to 10 Mohms, in response to a first, negative pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 Mv/cm and a time duration in the range from 1 ns to 10 ⁇ s.
- field direction is defined from the perspective of the electrode in contact with the oxygen-rich region 406 .
- the negative direction is from the top electrode 408 in contact with the oxygen-rich region 406 to the bottom electrode 402 in contact with the oxygen-deficient region 404 .
- the positive direction is defined herein as being from the electrode in contact with the oxygen-rich region 406 to the electrode in contact with the oxygen-deficient region 404 .
- the oxygen-rich and oxygen-deficient manganite regions 406 / 404 have a second resistance in the range of 100 ohms to 1 kohm in response to a second, positive pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 ⁇ s.
- the two manganite regions 404 and 406 have different resistance properties, to insure the asymmetrical characteristics of the cell 400 .
- the oxygen-deficient manganite region 404 changes resistance in response to an electric field.
- the oxygen-rich manganite region 406 maintains a constant resistance in response to an electric field.
- the oxygen-rich manganite region 406 has a thickness 410 in the range of 20 to 150 nanometers (nm).
- the oxygen-deficient manganite region 404 can have a thickness 412 in the range of 20 to 150 nm. Considered together, the oxygen-deficient manganite region 404 has a thickness 412 within 0.5 to 1.5 the thickness 410 of the oxygen-rich manganite region 406 .
- the present invention cell or memory film can be made geometrically symmetrical, yet have physically asymmetrical characteristics.
- the crystal structure of the memory resistor material is made practically uniform across the entire film. That is, from bottom electrode to the top electrode.
- the oxygen distribution is controlled through the memory resistor thin film, which in turn affects the device switching properties.
- FIGS. 5 a and 5 b are partial cross-sectional views of the memory cell of FIG. 4 during programming and erasing operations, respectively.
- the upper portion of the memory resistor thin film has a higher oxygen content region, while the lower portion of the memory resistor thin film has a lower oxygen content region.
- the device exhibits good memory programming properties if the oxygen density in the upper portion, and that in the lower portion of the memory resistor film, are reversed. In that situation, the programming pulse polarity would be the reverse of the ones shown.
- FIGS. 6 through 9 are diagrams of AES data for four memory resistors.
- the oxygen content of the four devices was controlled by an annealing process.
- the devices of FIGS. 6 and 7 are both fabricated with Pt top and bottom electrodes and a Pr 0.3 Ca 0.7 MnO 3 (PCMO) memory resistor material.
- the devices of FIGS. 8 and 9 are both fabricated with a Pt top electrode, an Ir bottom electrode, and a PCMO memory resistor film.
- FIG. 6 and FIG. 8 were annealed in oxygen at 525° C. for up to 40 minutes. Both these devices exhibit approximately equal portions of memory resistor thin film having a greater than 50% oxygen content, and a lower that 50% oxygen content. Because of the oxygen content distinction, both samples exhibit good programming properties. When the samples were annealed at 600° C. for more that 5 minutes, the oxygen content is higher than 50% across the entire thin film. Both these sample ( FIGS. 7 and 9 ) exhibit low resistivity. The resistance of these two samples does not response to a programming pulse.
- the oxygen content in the memory resistor material can be controlled by annealing in oxygen ambient atmosphere.
- MOD metalorganic spin deposition
- the film is annealed at temperature of no higher than 550° C., for no longer than one hour.
- the oxygen content can also be controlled through metalorganic chemical vapor deposition (MOCVD) or physical vapor deposition (PVD) process.
- FIG. 10 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory material. Although the method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. It should be understood that some of these steps may be skipped, performed in parallel, or performed without the requirement of maintaining a strict order of sequence.
- the method starts at Step 1000 .
- Step 1002 forms manganite.
- Step 1004 anneals the manganite in an oxygen atmosphere.
- Step 1004 may anneal the manganite at a temperature of less than 600 degrees C. for a period of time less than 1 hour.
- Step 1006 controls the oxygen content in the manganite in response to the annealing.
- Step 1008 controls resistance through the manganite in response to the oxygen content.
- Forming manganite in Step 1002 includes forming manganite from a material selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5.
- the manganite can be formed through a process such as PVD, MOCVD, or MOD, as mentioned above.
- controlling the oxygen content in the manganite in response to the annealing in Step 1006 includes forming an oxygen-rich RE 1-x AE x MnO y region where y is greater than 3. Then, controlling resistance through the manganite in response to the oxygen content in Step 1008 includes forming a low resistance in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite in response to the annealing in Step 1006 includes forming an oxygen-deficient RE 1-x AE x MnO y region where y is less than 3. Then, controlling resistance through the manganite in response to the oxygen content in Step 1008 includes forming a high resistance in the oxygen-deficient manganite region.
- Step 1006 forms an oxygen-rich RE 1-x AE x MnO y region where y is greater than 3, and an oxygen-deficient RE 1-x AE x MnO y region where y is less than 3.
- Step 1008 forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. More specifically, the oxygen-rich manganite region is adjacent, either overlying or underlying, the oxygen-deficient manganite region.
- Step 1010 applies a pulsed electric field to the manganite.
- Step 1012 changes the overall resistance through the manganite in response to the pulsed electric field.
- applying a pulsed electric field to the manganite in Step 1010 includes applying a first, negative pulsed electric field (where field direction is defined from the perspective of the oxygen-rich region) having a field strength in the range of 0.1 megavolts per centimeter (MV/cm) to 0.5 Mv/cm and a time duration in the range from 1 nanosecond (ns) to 10 microseconds ( ⁇ s).
- changing the overall resistance through the manganite in response to the pulsed electric field in Step 1012 includes creating an overall resistance in the range of 100 ohms to 10 megaohms (Mohms) in response to the first electric field.
- Step 1010 applies a second, positive pulsed electric field (as defined above) having a field strength in the range of 0.1 MV/cm to 0.5 Mv/cm and a time duration in the range from 1 ns to 10 ⁇ s. Then, Step 1012 creates an overall resistance in the range of 100 ohms to 1 kilo-ohm (kohm) in response to the second electric field.
- a second, positive pulsed electric field as defined above
- Step 1012 creates an overall resistance in the range of 100 ohms to 1 kilo-ohm (kohm) in response to the second electric field.
- changing the overall resistance through the manganite in response to the pulsed electric field includes substeps.
- Step 1012 a changes the resistance in the oxygen-deficient manganite region.
- Step 1012 b maintains a constant resistance in the oxygen-rich manganite region.
- FIG. 11 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory resistor or memory cell.
- the method starts at Step 1100 .
- Step 1102 forms a bottom electrode.
- Step 1104 forms manganite overlying the bottom electrode.
- Step 1106 forms a top electrode overlying the manganite.
- Step 1108 anneals the manganite in an oxygen atmosphere.
- Step 1108 may anneal the manganite at a temperature of less than 600 degrees C. for a period of time less than 1 hour.
- Step 1110 controls the oxygen content in the manganite in response to the annealing.
- Step 1112 controls resistance through the manganite in response to the oxygen content.
- Forming manganite in Step 1104 includes forming manganite from a material selected from the group including perovskite-type manganese oxides with the general formula RE 1-x AE x MnO y , where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5.
- the manganite can be formed through a process such as PVD, MOCVD, or MOD, as mentioned above.
- Forming a top electrode in Step 1106 includes forming a top electrode from a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir.
- forming a bottom electrode in Step 1102 includes forming a bottom electrode from a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir.
- the top and bottom electrode materials need not necessarily be the same.
- controlling the oxygen content in the manganite in response to the annealing in Step 1110 includes forming an oxygen-rich RE 1-x AE x MnO y region where y is greater than 3. Then, controlling resistance through the manganite in response to the oxygen content in Step 1112 includes forming a low resistance in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite in response to the annealing in Step 1110 includes forming an oxygen-deficient RE 1-x AE x MnO y region where y is less than 3. Then, controlling resistance through the manganite in response to the oxygen content in Step 1112 includes forming a high resistance in the oxygen-deficient manganite region.
- Step 1110 forms an oxygen-rich RE 1-x AE x MnO y region where y is greater than 3, and an oxygen-deficient RE 1-x AE x MnO y region where y is less than 3.
- Step 1112 forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. More specifically, the oxygen-rich manganite region is adjacent, either overlying or underlying, the oxygen-deficient manganite region.
- Step 1114 applies a pulsed electric field to the manganite.
- Step 1116 changes the overall resistance through the manganite in response to the pulsed electric field.
- applying a pulsed electric field to the manganite in Step 1114 includes applying a first, negative pulsed electric field (where field direction is defined from the perspective of the electrode in contact with the oxygen-rich region) having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 ⁇ s.
- changing the overall resistance through the manganite in response to the pulsed electric field in Step 1116 includes creating an overall resistance in the range of 100 ohms to 10 Mohms in response to the first electric field.
- Step 1114 applies a second, positive pulsed electric field (as defined above) having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 ⁇ s. Then, Step 1116 creates an overall resistance in the range of 100 ohms to 1 kohm in response to the second electric field.
- a second, positive pulsed electric field as defined above
- changing the overall resistance through the manganite in response to the pulsed electric field includes substeps.
- Step 1116 a changes the resistance in the oxygen-deficient manganite region.
- Step 1116 b maintains a constant resistance in the oxygen-rich manganite region.
- a memory cell where the memory properties are responsive to the oxygen content in the memory resistor material, and a method of fabricating such a memory cell have been provided. Examples have been given to illustrate features of the invention. However, the invention is not limited to merely these examples. Other variations and embodiments of the invention will occur to those skilled in the art.
Abstract
Description
- This application is a Divisional Application of a pending patent application entitled, OXYGEN CONTENT SYSTEM AND METHOD FOR CONTROLLING MEMORY RESISTANCE PROPERTIES, invented by Hsu et al., Ser. No. 10/442,628, filed May 21, 2003.
- 1. Field of the Invention
- This invention generally relates to integrated circuit (IC) memory resistor cell arrays and, more particularly, to an oxygen content system for controlling memory resistance properties in a memory resistor cell and a method for fabricating the same.
- 2. Description of the Related Art
- Conventionally, memory cells using a memory resistor material, such as colossal magnetoresistance (CMR) materials, are fabricated with large unpatterned conductive bottom electrodes, unpatterned CMR material, and relatively small top electrodes. These devices work in limited applications, but they are not suitable for dense memory array applications because of relatively large size of the cells.
- The CMR material can be said to have a non-volatile nature, as the resistance of the CMR material remains constant under most circumstances. However, when a high electric field induces current flow through the CMR material, a change in the CMR resistance can result. During a programming process, the resistivity of the memory resistor at the high field region near the electrode changes first. Experimental data shows that the resistivity of the material at the cathode, referred as terminal A, is increased while that at the anode, referred as terminal B, is decreased. During the erase process the pulse polarity is reversed. That is, the designation of cathode and anode are reversed. Then, the resistivity of the material near terminal A is decreased, and the resistivity near terminal B is increased.
- As the demand increases for cell memory, there is increased motivation to reduce the size of cells in the array. However, smaller feature sizes make the device more susceptible to process tolerance errors. Due to process tolerances, extremely small geometrically asymmetrical devices are difficult to reliably fabricate. However, an analysis (provided below) shows that fabricated memory cells that are sufficiently symmetrical, will not work properly. Even if these symmetrical devices can be programmed, the net resistance change from high resistance-state to low resistance-state may be relatively low.
- It would be advantageous to build memory cells with enough asymmetry to guarantee significant resistance state changes despite process tolerancing.
- The present invention describes a thin film resistance memory device suitable for non-volatile memory array and analog resistance applications. The present invention memory cell can be reliably programmed, even if fabricated as a resistive non-volatile ultra small size memory cell, because of its asymmetrical characteristics.
- Accordingly, a method is provided for controlling the resistance properties in a memory material. The method comprises: forming manganite; annealing the manganite in an oxygen atmosphere; controlling the oxygen content in the manganite in response to the annealing; and, controlling resistance through the manganite in response to the oxygen content. The manganite is a material selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5.
- In some aspects of the method, controlling the oxygen content in the manganite includes forming an oxygen-rich RE1-xAExMnOy region where y is greater than 3. A low resistance results in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite includes forming an oxygen-deficient RE1-xAExMnOy region where y is less than 3. A high resistance is formed in the oxygen-deficient manganite region. More specifically, the process forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. For example, the oxygen-rich manganite region may overlie the oxygen-deficient manganite region.
- In some aspects the method further comprises: applying a pulsed electric field to the manganite; and, changing the overall resistance through the manganite in response to the pulsed electric field. More specifically, changing the overall resistance through the manganite in response to the pulsed electric field includes: changing the resistance in the oxygen-deficient manganite region; and, maintaining a constant resistance in the oxygen-rich manganite region.
- Additional details of the above-described method and an oxygen content-controlled memory resistor device are provided below.
-
FIGS. 1A and 1B are partial cross-sectional views of a memory cell during programming (FIG. 1A ) and erasing (FIG. 1B ) operations. -
FIGS. 2A and 2B are partial cross-sectional views of a memory cell, where the memory resistor has a cylindrical shape and is embedded in oxide or any suitable insulator. -
FIG. 3 is partial cross-sectional view of the present invention memory resistance film with controlled oxygen content. -
FIG. 4 is a partial cross-sectional view of the present invention memory cell with controlled oxygen content. -
FIGS. 5 a and 5 b are partial cross-sectional views of the memory cell ofFIG. 4 during programming and erasing operations, respectively. -
FIGS. 6 through 9 are diagrams of AES data for four memory resistors. -
FIG. 10 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory material. -
FIG. 11 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory resistor or memory cell. -
FIGS. 1A and 1B are partial cross-sectional views of a memory cell during programming (FIG. 1A ) and erasing (FIG. 1B ) operations. The top and bottom electrodes are identical and the memory resistance material is uniform throughout. If the geometric structure of the device could be made perfectly symmetrical, the net resistance would remains constant, in a high-resistance state, when either a negative field (FIG. 1A ) or a positive field (FIG. 1B ) is applied. In such circumstances, programming is not possible. Therefore, a perfectly symmetrical device structure, such as one inFIGS. 1A and 1B , is not practical. - More specifically, the geometrically symmetrical memory cell has a high current density near the electrodes (regions A and B), and a low current density in the center portion of the device, in the presence of an electric field. As a result, the resistivity of the CMR material near the top and bottom electrodes is changed. For example, the memory cell can be programmed to be in the high-resistance state if the resistivity of the memory resistor material near the top electrode is increased, and the resistivity of memory resistor material near the bottom electrode is decreased. When the polarity of the electric pulse applied to top electrode is reversed (becomes a positive pulse,
FIG. 1B ), the material near the top electrode (Region A) becomes low resistance (RL), while the material near the bottom electrode (Region B) becomes high resistance (RH). However, the overall resistance of the memory resistance remains the same, still in the high-resistance state. Therefore, it is not possible to program the memory resistor to the low-resistance state. - Since region A and region B are very close to the top and bottom electrode, respectively, and their thicknesses may be as thin as a 10 nanometers (nm), the above-described effect may be mistakenly classified as an interface effect. However, memory is not an interface property change, but is a bulk resistivity change.
-
FIGS. 2A and 2B are partial cross-sectional views of a memory cell, where the memory resistor has a cylindrical shape and is embedded in oxide or any suitable insulator. The field intensity is high near both top and bottom electrodes. Since the field direction near the top electrode is opposite that near the bottom electrode, the resistivity of the memory resistor material near the top electrode is increased while the resistivity of the memory resistor material near the bottom electrode is reduced. As a result, the memory resistance is programmed to the high-resistance state regardless of whether a positive or negative pulse is applied to the top electrode. Again, a geometrically symmetrical structure is not suitable for resistor memory cell. -
FIG. 3 is partial cross-sectional view of the present invention memory resistance film with controlled oxygen content. Thefilm 300 comprises an oxygen-deficient manganite region 302 and an oxygen-rich manganite region 304, adjacent the oxygen-deficient manganite region 302. As shown, the oxygen-rich manganite region 304 overlies the oxygen-deficient region 302. However, in other aspects (not shown), the oxygen-deficient manganite region 302 may overlie the oxygen-rich manganite region 304. The oxygen-rich manganite region 304 is selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5, and y being greater than 3. The oxygen-deficient manganite region 302 is selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where y is less than 3. - The oxygen-
rich manganite region 304 has a resistance, less than the resistance of the oxygen-deficient manganite region 302. Together, the oxygen-rich and oxygen-deficient manganite regions 304/302 have an overall first resistance responsive to a negative electric field. The oxygen-rich and oxygen-deficient manganite regions 304/302 have an overall second resistance, less than the first resistance, responsive to a positive electric field. As used herein, field direction direction is defined from the perspective of the oxygen-rich manganite region 304, assuming that the oxygen-rich region 304 overlies the oxygen-deficient region 302, as shown inFIG. 3 . In other words, the negative direction is from the oxygen-deficient region 302 to the oxygen-rich region 304. The positive direction is defined herein as being from the oxygen-rich region 304 to the oxygen-deficient region 302. - More specifically, the oxygen-rich and oxygen-
deficient manganite regions 304/302 have a first resistance in the range of 100 ohms to 10 megaohms (Mohms), in response to a first, negative pulsed electric field having a field strength in the range of 0.1 megavolts per centimeter (MV/cm) to 0.5 MV/cm and a time duration in the range from 1 nanosecond (ns) to 10 microseconds (μs). - The oxygen-rich and oxygen-
deficient manganite regions 304/302 have a second resistance in the range of 100 ohms to 1 kilo-ohm (kohm) in response to a second, positive pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 μs. - The two
manganite regions film 300. The oxygen-deficient manganite region 302 changes resistance in response to an electric field. However, the oxygen-rich manganite region 304 maintains a constant resistance in response to an electric field. - In some aspects, the oxygen-
rich manganite region 304 has athickness 306 in the range of 20 to 150 nanometers (nm). Likewise, the oxygen-deficient manganite region 302 can have athickness 308 in the range of 20 to 150 nm. Considered together, the oxygen-deficient manganite region 302 has athickness 308 within 0.5 to 1.5 thethickness 306 of the oxygen-rich manganite region 304. -
FIG. 4 is a partial cross-sectional view of the present invention memory cell with controlled oxygen content. The cell 400 comprises abottom electrode 402 and an oxygen-deficient manganite region 404 overlying thebottom electrode 402. An oxygen-rich manganite region 406 is adjacent the oxygen-deficient manganite region 404 and atop electrode 408 overlies the oxygen-rich manganite region 406 and oxygen-deficient manganite region 404. As shown, the oxygen-rich manganite region 406 overlies the oxygen-deficient region 404. However, in other aspects (not shown), the oxygen-deficient manganite region 404 may overlie the oxygen-rich manganite region 406. - The oxygen-
rich manganite region 406 is selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5, and y being greater than 3. The oxygen-deficient manganite region 404 is selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where y is less than 3. - The
top electrode 408 is a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir. Likewise, thebottom electrode 402 is a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir. Thetop electrode 408 need not necessarily be the same material as thebottom electrode 402. - The oxygen-
rich manganite region 406 has a resistance, less than the resistance of the oxygen-deficient manganite region 404. Together, the oxygen-rich and oxygen-deficient manganite regions 406/404 have an overall first resistance responsive to a negative electric field. The oxygen-rich and oxygen-deficient manganite regions 406/404 have an overall second resistance, less than the first resistance, responsive to a positive electric field. - More specifically, the oxygen-rich and oxygen-
deficient manganite regions 406/404 have a first resistance in the range of 100 ohms to 10 Mohms, in response to a first, negative pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 Mv/cm and a time duration in the range from 1 ns to 10 μs. As used herein, field direction is defined from the perspective of the electrode in contact with the oxygen-rich region 406. In the shown example, the negative direction is from thetop electrode 408 in contact with the oxygen-rich region 406 to thebottom electrode 402 in contact with the oxygen-deficient region 404. The positive direction is defined herein as being from the electrode in contact with the oxygen-rich region 406 to the electrode in contact with the oxygen-deficient region 404. The oxygen-rich and oxygen-deficient manganite regions 406/404 have a second resistance in the range of 100 ohms to 1 kohm in response to a second, positive pulsed electric field having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 μs. - The two
manganite regions deficient manganite region 404 changes resistance in response to an electric field. However, the oxygen-rich manganite region 406 maintains a constant resistance in response to an electric field. - In some aspects, the oxygen-
rich manganite region 406 has athickness 410 in the range of 20 to 150 nanometers (nm). Likewise, the oxygen-deficient manganite region 404 can have athickness 412 in the range of 20 to 150 nm. Considered together, the oxygen-deficient manganite region 404 has athickness 412 within 0.5 to 1.5 thethickness 410 of the oxygen-rich manganite region 406. - The present invention cell or memory film can be made geometrically symmetrical, yet have physically asymmetrical characteristics. With the present invention device, the crystal structure of the memory resistor material is made practically uniform across the entire film. That is, from bottom electrode to the top electrode. However, the oxygen distribution is controlled through the memory resistor thin film, which in turn affects the device switching properties.
-
FIGS. 5 a and 5 b are partial cross-sectional views of the memory cell ofFIG. 4 during programming and erasing operations, respectively. The upper portion of the memory resistor thin film has a higher oxygen content region, while the lower portion of the memory resistor thin film has a lower oxygen content region. The device exhibits good memory programming properties if the oxygen density in the upper portion, and that in the lower portion of the memory resistor film, are reversed. In that situation, the programming pulse polarity would be the reverse of the ones shown. -
FIGS. 6 through 9 are diagrams of AES data for four memory resistors. The oxygen content of the four devices was controlled by an annealing process. The devices ofFIGS. 6 and 7 are both fabricated with Pt top and bottom electrodes and a Pr0.3Ca0.7MnO3 (PCMO) memory resistor material. The devices ofFIGS. 8 and 9 are both fabricated with a Pt top electrode, an Ir bottom electrode, and a PCMO memory resistor film. - The devices of
FIG. 6 andFIG. 8 were annealed in oxygen at 525° C. for up to 40 minutes. Both these devices exhibit approximately equal portions of memory resistor thin film having a greater than 50% oxygen content, and a lower that 50% oxygen content. Because of the oxygen content distinction, both samples exhibit good programming properties. When the samples were annealed at 600° C. for more that 5 minutes, the oxygen content is higher than 50% across the entire thin film. Both these sample (FIGS. 7 and 9 ) exhibit low resistivity. The resistance of these two samples does not response to a programming pulse. - The oxygen content in the memory resistor material can be controlled by annealing in oxygen ambient atmosphere. For a metalorganic spin deposition (MOD) film, the film is annealed at temperature of no higher than 550° C., for no longer than one hour. The oxygen content can also be controlled through metalorganic chemical vapor deposition (MOCVD) or physical vapor deposition (PVD) process.
-
FIG. 10 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory material. Although the method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. It should be understood that some of these steps may be skipped, performed in parallel, or performed without the requirement of maintaining a strict order of sequence. The method starts atStep 1000. -
Step 1002 forms manganite.Step 1004 anneals the manganite in an oxygen atmosphere. For example,Step 1004 may anneal the manganite at a temperature of less than 600 degrees C. for a period of time less than 1 hour.Step 1006 controls the oxygen content in the manganite in response to the annealing.Step 1008 controls resistance through the manganite in response to the oxygen content. - Forming manganite in
Step 1002 includes forming manganite from a material selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5. The manganite can be formed through a process such as PVD, MOCVD, or MOD, as mentioned above. - In some aspects, controlling the oxygen content in the manganite in response to the annealing in
Step 1006 includes forming an oxygen-rich RE1-xAExMnOy region where y is greater than 3. Then, controlling resistance through the manganite in response to the oxygen content inStep 1008 includes forming a low resistance in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite in response to the annealing inStep 1006 includes forming an oxygen-deficient RE1-xAExMnOy region where y is less than 3. Then, controlling resistance through the manganite in response to the oxygen content inStep 1008 includes forming a high resistance in the oxygen-deficient manganite region. - Typically,
Step 1006 forms an oxygen-rich RE1-xAExMnOy region where y is greater than 3, and an oxygen-deficient RE1-xAExMnOy region where y is less than 3. Then,Step 1008 forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. More specifically, the oxygen-rich manganite region is adjacent, either overlying or underlying, the oxygen-deficient manganite region. -
Step 1010 applies a pulsed electric field to the manganite.Step 1012 changes the overall resistance through the manganite in response to the pulsed electric field. - In some aspects, applying a pulsed electric field to the manganite in
Step 1010 includes applying a first, negative pulsed electric field (where field direction is defined from the perspective of the oxygen-rich region) having a field strength in the range of 0.1 megavolts per centimeter (MV/cm) to 0.5 Mv/cm and a time duration in the range from 1 nanosecond (ns) to 10 microseconds (μs). Then, changing the overall resistance through the manganite in response to the pulsed electric field inStep 1012 includes creating an overall resistance in the range of 100 ohms to 10 megaohms (Mohms) in response to the first electric field. - In other aspects,
Step 1010 applies a second, positive pulsed electric field (as defined above) having a field strength in the range of 0.1 MV/cm to 0.5 Mv/cm and a time duration in the range from 1 ns to 10 μs. Then,Step 1012 creates an overall resistance in the range of 100 ohms to 1 kilo-ohm (kohm) in response to the second electric field. - In some aspects, changing the overall resistance through the manganite in response to the pulsed electric field (Step 1012) includes substeps.
Step 1012 a changes the resistance in the oxygen-deficient manganite region.Step 1012 b maintains a constant resistance in the oxygen-rich manganite region. -
FIG. 11 is a flowchart illustrating the present invention method for controlling the resistance properties in a memory resistor or memory cell. The method starts atStep 1100.Step 1102 forms a bottom electrode.Step 1104 forms manganite overlying the bottom electrode.Step 1106 forms a top electrode overlying the manganite.Step 1108 anneals the manganite in an oxygen atmosphere. For example,Step 1108 may anneal the manganite at a temperature of less than 600 degrees C. for a period of time less than 1 hour.Step 1110 controls the oxygen content in the manganite in response to the annealing.Step 1112 controls resistance through the manganite in response to the oxygen content. - Forming manganite in
Step 1104 includes forming manganite from a material selected from the group including perovskite-type manganese oxides with the general formula RE1-xAExMnOy, where RE is a rare earth ion and AE is an alkaline-earth ion, with x in the range between 0.1 and 0.5. The manganite can be formed through a process such as PVD, MOCVD, or MOD, as mentioned above. - Forming a top electrode in
Step 1106 includes forming a top electrode from a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir. Likewise, forming a bottom electrode inStep 1102 includes forming a bottom electrode from a material such as Pt, TiN, TaN, TiAlN, TaAlN, Ag, Au, or Ir. The top and bottom electrode materials need not necessarily be the same. - In some aspects, controlling the oxygen content in the manganite in response to the annealing in
Step 1110 includes forming an oxygen-rich RE1-xAExMnOy region where y is greater than 3. Then, controlling resistance through the manganite in response to the oxygen content inStep 1112 includes forming a low resistance in the oxygen-rich manganite region. In other aspects, controlling the oxygen content in the manganite in response to the annealing inStep 1110 includes forming an oxygen-deficient RE1-xAExMnOy region where y is less than 3. Then, controlling resistance through the manganite in response to the oxygen content inStep 1112 includes forming a high resistance in the oxygen-deficient manganite region. - Typically,
Step 1110 forms an oxygen-rich RE1-xAExMnOy region where y is greater than 3, and an oxygen-deficient RE1-xAExMnOy region where y is less than 3. Then,Step 1112 forms a first, low resistance in the oxygen-rich manganite region and a second resistance in the oxygen-deficient manganite region, higher than the first resistance. More specifically, the oxygen-rich manganite region is adjacent, either overlying or underlying, the oxygen-deficient manganite region. -
Step 1114 applies a pulsed electric field to the manganite.Step 1116 changes the overall resistance through the manganite in response to the pulsed electric field. - In some aspects, applying a pulsed electric field to the manganite in
Step 1114 includes applying a first, negative pulsed electric field (where field direction is defined from the perspective of the electrode in contact with the oxygen-rich region) having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 μs. Then, changing the overall resistance through the manganite in response to the pulsed electric field inStep 1116 includes creating an overall resistance in the range of 100 ohms to 10 Mohms in response to the first electric field. - In other aspects,
Step 1114 applies a second, positive pulsed electric field (as defined above) having a field strength in the range of 0.1 MV/cm to 0.5 MV/cm and a time duration in the range from 1 ns to 10 μs. Then,Step 1116 creates an overall resistance in the range of 100 ohms to 1 kohm in response to the second electric field. - In some aspects, changing the overall resistance through the manganite in response to the pulsed electric field (Step 1116) includes substeps.
Step 1116 a changes the resistance in the oxygen-deficient manganite region.Step 1116 b maintains a constant resistance in the oxygen-rich manganite region. - A memory cell, where the memory properties are responsive to the oxygen content in the memory resistor material, and a method of fabricating such a memory cell have been provided. Examples have been given to illustrate features of the invention. However, the invention is not limited to merely these examples. Other variations and embodiments of the invention will occur to those skilled in the art.
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/226,998 US7148533B2 (en) | 2003-05-21 | 2005-09-14 | Memory resistance film with controlled oxygen content |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/442,628 US6972238B2 (en) | 2003-05-21 | 2003-05-21 | Oxygen content system and method for controlling memory resistance properties |
US11/226,998 US7148533B2 (en) | 2003-05-21 | 2005-09-14 | Memory resistance film with controlled oxygen content |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/442,628 Division US6972238B2 (en) | 2003-05-21 | 2003-05-21 | Oxygen content system and method for controlling memory resistance properties |
Publications (2)
Publication Number | Publication Date |
---|---|
US20060011897A1 true US20060011897A1 (en) | 2006-01-19 |
US7148533B2 US7148533B2 (en) | 2006-12-12 |
Family
ID=33450250
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/442,628 Expired - Lifetime US6972238B2 (en) | 2003-05-21 | 2003-05-21 | Oxygen content system and method for controlling memory resistance properties |
US11/226,998 Expired - Lifetime US7148533B2 (en) | 2003-05-21 | 2005-09-14 | Memory resistance film with controlled oxygen content |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/442,628 Expired - Lifetime US6972238B2 (en) | 2003-05-21 | 2003-05-21 | Oxygen content system and method for controlling memory resistance properties |
Country Status (7)
Country | Link |
---|---|
US (2) | US6972238B2 (en) |
EP (1) | EP1498952B1 (en) |
JP (1) | JP4895070B2 (en) |
KR (1) | KR100706014B1 (en) |
CN (1) | CN1574215A (en) |
DE (1) | DE602004011585T2 (en) |
TW (1) | TWI246711B (en) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050258027A1 (en) * | 2003-09-15 | 2005-11-24 | Makoto Nagashima | Back-biased face target sputtering based programmable logic device |
US20060081467A1 (en) * | 2004-10-15 | 2006-04-20 | Makoto Nagashima | Systems and methods for magnetron deposition |
US20060081466A1 (en) * | 2004-10-15 | 2006-04-20 | Makoto Nagashima | High uniformity 1-D multiple magnet magnetron source |
US20060276036A1 (en) * | 2004-10-15 | 2006-12-07 | Makoto Nagashima | Systems and methods for plasma etching |
US20070084716A1 (en) * | 2005-10-16 | 2007-04-19 | Makoto Nagashima | Back-biased face target sputtering based high density non-volatile data storage |
US20070084717A1 (en) * | 2005-10-16 | 2007-04-19 | Makoto Nagashima | Back-biased face target sputtering based high density non-volatile caching data storage |
US20070224770A1 (en) * | 2006-03-25 | 2007-09-27 | Makoto Nagashima | Systems and methods for fabricating self-aligned memory cell |
US20080011603A1 (en) * | 2006-07-14 | 2008-01-17 | Makoto Nagashima | Ultra high vacuum deposition of PCMO material |
US20080011600A1 (en) * | 2006-07-14 | 2008-01-17 | Makoto Nagashima | Dual hexagonal shaped plasma source |
US20100200832A1 (en) * | 2007-08-22 | 2010-08-12 | Fujitsu Limited | Resistance variable element |
US20100308298A1 (en) * | 2008-10-01 | 2010-12-09 | Takeki Ninomiya | Nonvolatile memory element and nonvolatile memory device incorporating nonvolatile memory element |
US7932548B2 (en) | 2006-07-14 | 2011-04-26 | 4D-S Pty Ltd. | Systems and methods for fabricating self-aligned memory cell |
US8308915B2 (en) | 2006-09-14 | 2012-11-13 | 4D-S Pty Ltd. | Systems and methods for magnetron deposition |
US8350245B2 (en) | 2008-12-10 | 2013-01-08 | Panasonic Corporation | Variable resistance element and nonvolatile semiconductor memory device using the same |
US20130234095A1 (en) * | 2012-03-07 | 2013-09-12 | Masanobu Baba | Nonvolatile semiconductor storage device |
Families Citing this family (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7884349B2 (en) * | 2002-08-02 | 2011-02-08 | Unity Semiconductor Corporation | Selection device for re-writable memory |
EP1654765A2 (en) * | 2004-01-10 | 2006-05-10 | Hvvi Semiconductors, Inc. | Power semiconductor device and method therefor cross reference to related applications |
US20060171200A1 (en) | 2004-02-06 | 2006-08-03 | Unity Semiconductor Corporation | Memory using mixed valence conductive oxides |
US7538338B2 (en) * | 2004-09-03 | 2009-05-26 | Unity Semiconductor Corporation | Memory using variable tunnel barrier widths |
US7082052B2 (en) | 2004-02-06 | 2006-07-25 | Unity Semiconductor Corporation | Multi-resistive state element with reactive metal |
KR101051704B1 (en) | 2004-04-28 | 2011-07-25 | 삼성전자주식회사 | Memory device using multilayer with resistive gradient |
US7029982B1 (en) * | 2004-10-21 | 2006-04-18 | Sharp Laboratories Of America, Inc. | Method of affecting RRAM characteristics by doping PCMO thin films |
US8530963B2 (en) * | 2005-01-06 | 2013-09-10 | Estivation Properties Llc | Power semiconductor device and method therefor |
KR100693409B1 (en) * | 2005-01-14 | 2007-03-12 | 광주과학기술원 | Nonvolatile Memory Device Based on Resistance Switching of Oxide ? Method Thereof |
JP2008060091A (en) * | 2005-01-14 | 2008-03-13 | Matsushita Electric Ind Co Ltd | Resistance variable element |
WO2006101152A1 (en) | 2005-03-23 | 2006-09-28 | National Institute Of Advanced Industrial Science And Technology | Nonvolatile memory element |
US8031509B2 (en) * | 2008-12-19 | 2011-10-04 | Unity Semiconductor Corporation | Conductive metal oxide structures in non-volatile re-writable memory devices |
US8314024B2 (en) | 2008-12-19 | 2012-11-20 | Unity Semiconductor Corporation | Device fabrication |
US20130082232A1 (en) | 2011-09-30 | 2013-04-04 | Unity Semiconductor Corporation | Multi Layered Conductive Metal Oxide Structures And Methods For Facilitating Enhanced Performance Characteristics Of Two Terminal Memory Cells |
JP4843259B2 (en) * | 2005-06-10 | 2011-12-21 | シャープ株式会社 | Method for manufacturing variable resistance element |
JP4783070B2 (en) * | 2005-06-24 | 2011-09-28 | シャープ株式会社 | Semiconductor memory device and manufacturing method thereof |
KR100657966B1 (en) * | 2005-08-11 | 2006-12-14 | 삼성전자주식회사 | Manufacturing method of memory device for stablizing reset current |
KR100647333B1 (en) * | 2005-08-31 | 2006-11-23 | 삼성전자주식회사 | Nonvolatile memory device and manufacturing method for the same |
JP4228033B2 (en) | 2006-03-08 | 2009-02-25 | パナソニック株式会社 | Nonvolatile memory element, nonvolatile memory device, and manufacturing method thereof |
US7656003B2 (en) * | 2006-08-25 | 2010-02-02 | Hvvi Semiconductors, Inc | Electrical stress protection apparatus and method of manufacture |
JP5007724B2 (en) * | 2006-09-28 | 2012-08-22 | 富士通株式会社 | Variable resistance element |
US8766224B2 (en) | 2006-10-03 | 2014-07-01 | Hewlett-Packard Development Company, L.P. | Electrically actuated switch |
WO2008047711A1 (en) | 2006-10-16 | 2008-04-24 | Panasonic Corporation | Non-volatile storage element array, and its manufacturing method |
US7372753B1 (en) * | 2006-10-19 | 2008-05-13 | Unity Semiconductor Corporation | Two-cycle sensing in a two-terminal memory array having leakage current |
US7379364B2 (en) * | 2006-10-19 | 2008-05-27 | Unity Semiconductor Corporation | Sensing a signal in a two-terminal memory array having leakage current |
US7888746B2 (en) * | 2006-12-15 | 2011-02-15 | Hvvi Semiconductors, Inc. | Semiconductor structure and method of manufacture |
CN100550459C (en) * | 2007-01-12 | 2009-10-14 | 中国科学院上海硅酸盐研究所 | Improve the method for pulse trigger resistor random memory fatigue resisting characteristic |
JP4805865B2 (en) * | 2007-03-19 | 2011-11-02 | シャープ株式会社 | Variable resistance element |
US7995371B2 (en) * | 2007-07-26 | 2011-08-09 | Unity Semiconductor Corporation | Threshold device for a memory array |
WO2009072213A1 (en) * | 2007-12-07 | 2009-06-11 | Fujitsu Limited | Resistance change-type memory device, nonvolatile memory device, and method for manufacturing them |
US8208284B2 (en) * | 2008-03-07 | 2012-06-26 | Unity Semiconductor Corporation | Data retention structure for non-volatile memory |
JP5488458B2 (en) | 2008-04-07 | 2014-05-14 | 日本電気株式会社 | Resistance change element and manufacturing method thereof |
JP5476686B2 (en) * | 2008-07-24 | 2014-04-23 | 富士通株式会社 | Resistance change element and resistance change element manufacturing method |
CN101878507B (en) * | 2008-09-30 | 2013-10-23 | 松下电器产业株式会社 | Method for driving resistance change element, initial processing method, and nonvolatile storage device |
US8263420B2 (en) | 2008-11-12 | 2012-09-11 | Sandisk 3D Llc | Optimized electrodes for Re-RAM |
US8027215B2 (en) | 2008-12-19 | 2011-09-27 | Unity Semiconductor Corporation | Array operation using a schottky diode as a non-ohmic isolation device |
US8431921B2 (en) * | 2009-01-13 | 2013-04-30 | Hewlett-Packard Development Company, L.P. | Memristor having a triangular shaped electrode |
KR101039191B1 (en) | 2009-01-19 | 2011-06-03 | 한양대학교 산학협력단 | Nonvolatile memory device and method of manufacturing the same |
KR20120016044A (en) * | 2009-03-27 | 2012-02-22 | 휴렛-팩커드 디벨롭먼트 컴퍼니, 엘.피. | Switchable junction with intrinsic diode |
US20120018698A1 (en) * | 2009-08-31 | 2012-01-26 | Jianhua Yang | Low-power nanoscale switching device with an amorphous switching material |
US8045364B2 (en) * | 2009-12-18 | 2011-10-25 | Unity Semiconductor Corporation | Non-volatile memory device ion barrier |
US7832090B1 (en) | 2010-02-25 | 2010-11-16 | Unity Semiconductor Corporation | Method of making a planar electrode |
DE102010011646A1 (en) | 2010-03-10 | 2011-09-15 | Technische Universität Bergakademie Freiberg | A process for producing a nonvolatile electronic data memory based on a crystalline oxide having a perovskite structure |
US8542518B2 (en) | 2010-03-31 | 2013-09-24 | Hewlett-Packard Development Company, L.P. | Photo-responsive memory resistor and method of operation |
CN102237309B (en) * | 2010-05-06 | 2013-06-12 | 复旦大学 | Method for integrating manganese-oxide-based resistive memory with copper interconnection rear end process |
US9508425B2 (en) * | 2010-06-24 | 2016-11-29 | The Regents Of The University Of Michigan | Nanoscale metal oxide resistive switching element |
CN102544354B (en) * | 2010-08-25 | 2014-04-02 | 复旦大学 | CuxO resistance type memorizer integrated with copper interconnection back-end structure and preparation method thereof |
KR101925448B1 (en) * | 2012-12-17 | 2018-12-05 | 에스케이하이닉스 주식회사 | Resistance variable memory device and method for fabricating the same |
CN108091760B (en) | 2016-11-23 | 2019-11-22 | 清华大学 | Regulate and control the method for hydrogeneous transition metal oxide phase transformation |
CN108091913B (en) | 2016-11-23 | 2020-01-21 | 清华大学 | Solid fuel cell and method for preparing solid electrolyte |
CN108091759B (en) | 2016-11-23 | 2019-07-09 | 清华大学 | Phase transformation electronic device |
CN108091870B (en) | 2016-11-23 | 2021-02-26 | 清华大学 | Hydrogen-containing transition metal oxide, preparation method and primary battery |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040160817A1 (en) * | 2002-08-02 | 2004-08-19 | Unity Semiconductor Corporation | Non-volatile memory with a single transistor and resistive memory element |
US6870755B2 (en) * | 2002-08-02 | 2005-03-22 | Unity Semiconductor Corporation | Re-writable memory with non-linear memory element |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6117571A (en) * | 1997-03-28 | 2000-09-12 | Advanced Technology Materials, Inc. | Compositions and method for forming doped A-site deficient thin-film manganate layers on a substrate |
KR20040036404A (en) * | 2002-10-25 | 2004-04-30 | 주식회사 마이크로 세미콘 | Multi Dressing Chuck Table |
-
2003
- 2003-05-21 US US10/442,628 patent/US6972238B2/en not_active Expired - Lifetime
-
2004
- 2004-04-27 JP JP2004132265A patent/JP4895070B2/en not_active Expired - Lifetime
- 2004-05-19 DE DE602004011585T patent/DE602004011585T2/en active Active
- 2004-05-19 EP EP04011966A patent/EP1498952B1/en active Active
- 2004-05-20 TW TW093114305A patent/TWI246711B/en active
- 2004-05-21 KR KR1020040036404A patent/KR100706014B1/en active IP Right Grant
- 2004-05-21 CN CNA2004100457174A patent/CN1574215A/en active Pending
-
2005
- 2005-09-14 US US11/226,998 patent/US7148533B2/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040160817A1 (en) * | 2002-08-02 | 2004-08-19 | Unity Semiconductor Corporation | Non-volatile memory with a single transistor and resistive memory element |
US6870755B2 (en) * | 2002-08-02 | 2005-03-22 | Unity Semiconductor Corporation | Re-writable memory with non-linear memory element |
Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050258027A1 (en) * | 2003-09-15 | 2005-11-24 | Makoto Nagashima | Back-biased face target sputtering based programmable logic device |
US20070007124A1 (en) * | 2003-09-15 | 2007-01-11 | Makoto Nagashima | Back-biased face target sputtering based memory with low oxygen flow rate |
US20070119705A1 (en) * | 2003-09-15 | 2007-05-31 | Makoto Nagashima | Back-biased face target sputtering based memory data sensing technique |
US20060081467A1 (en) * | 2004-10-15 | 2006-04-20 | Makoto Nagashima | Systems and methods for magnetron deposition |
US20060081466A1 (en) * | 2004-10-15 | 2006-04-20 | Makoto Nagashima | High uniformity 1-D multiple magnet magnetron source |
US20060276036A1 (en) * | 2004-10-15 | 2006-12-07 | Makoto Nagashima | Systems and methods for plasma etching |
US20070084716A1 (en) * | 2005-10-16 | 2007-04-19 | Makoto Nagashima | Back-biased face target sputtering based high density non-volatile data storage |
US20070084717A1 (en) * | 2005-10-16 | 2007-04-19 | Makoto Nagashima | Back-biased face target sputtering based high density non-volatile caching data storage |
US20070224770A1 (en) * | 2006-03-25 | 2007-09-27 | Makoto Nagashima | Systems and methods for fabricating self-aligned memory cell |
US8395199B2 (en) | 2006-03-25 | 2013-03-12 | 4D-S Pty Ltd. | Systems and methods for fabricating self-aligned memory cell |
US20080011600A1 (en) * | 2006-07-14 | 2008-01-17 | Makoto Nagashima | Dual hexagonal shaped plasma source |
US7932548B2 (en) | 2006-07-14 | 2011-04-26 | 4D-S Pty Ltd. | Systems and methods for fabricating self-aligned memory cell |
US8367513B2 (en) | 2006-07-14 | 2013-02-05 | 4D-S Pty Ltd. | Systems and methods for fabricating self-aligned memory cell |
US20080011603A1 (en) * | 2006-07-14 | 2008-01-17 | Makoto Nagashima | Ultra high vacuum deposition of PCMO material |
US8454810B2 (en) | 2006-07-14 | 2013-06-04 | 4D-S Pty Ltd. | Dual hexagonal shaped plasma source |
US8308915B2 (en) | 2006-09-14 | 2012-11-13 | 4D-S Pty Ltd. | Systems and methods for magnetron deposition |
US20100200832A1 (en) * | 2007-08-22 | 2010-08-12 | Fujitsu Limited | Resistance variable element |
US20100308298A1 (en) * | 2008-10-01 | 2010-12-09 | Takeki Ninomiya | Nonvolatile memory element and nonvolatile memory device incorporating nonvolatile memory element |
US8441060B2 (en) | 2008-10-01 | 2013-05-14 | Panasonic Corporation | Nonvolatile memory element and nonvolatile memory device incorporating nonvolatile memory element |
US8350245B2 (en) | 2008-12-10 | 2013-01-08 | Panasonic Corporation | Variable resistance element and nonvolatile semiconductor memory device using the same |
US20130234095A1 (en) * | 2012-03-07 | 2013-09-12 | Masanobu Baba | Nonvolatile semiconductor storage device |
US8772753B2 (en) * | 2012-03-07 | 2014-07-08 | Kabushiki Kaisha Toshiba | Nonvolatile semiconductor storage device |
Also Published As
Publication number | Publication date |
---|---|
US6972238B2 (en) | 2005-12-06 |
JP2004349690A (en) | 2004-12-09 |
US20040235200A1 (en) | 2004-11-25 |
TW200511367A (en) | 2005-03-16 |
JP4895070B2 (en) | 2012-03-14 |
US7148533B2 (en) | 2006-12-12 |
EP1498952B1 (en) | 2008-01-30 |
TWI246711B (en) | 2006-01-01 |
KR20040101069A (en) | 2004-12-02 |
KR100706014B1 (en) | 2007-04-11 |
DE602004011585D1 (en) | 2008-03-20 |
EP1498952A3 (en) | 2006-05-24 |
DE602004011585T2 (en) | 2009-02-19 |
CN1574215A (en) | 2005-02-02 |
EP1498952A2 (en) | 2005-01-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7148533B2 (en) | Memory resistance film with controlled oxygen content | |
US7214583B2 (en) | Memory cell with an asymmetric crystalline structure | |
US7029924B2 (en) | Buffered-layer memory cell | |
US7569459B2 (en) | Nonvolatile programmable resistor memory cell | |
US8009454B2 (en) | Resistance random access memory device and a method of manufacturing the same | |
US6965137B2 (en) | Multi-layer conductive memory device | |
US7974117B2 (en) | Non-volatile memory cell with programmable unipolar switching element | |
US20080011996A1 (en) | Multi-layer device with switchable resistance | |
JP2010123989A (en) | Asymmetric memory cell | |
WO2006101152A1 (en) | Nonvolatile memory element | |
US7932505B2 (en) | Perovskite transition metal oxide nonvolatile memory element | |
US7518213B2 (en) | Nonvolatile variable resistance memory device and method of fabricating the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: SHARP KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SHARP LABORATORIES OF AMERICA, INC.;REEL/FRAME:019795/0695 Effective date: 20070910 Owner name: SHARP KABUSHIKI KAISHA,JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SHARP LABORATORIES OF AMERICA, INC.;REEL/FRAME:019795/0695 Effective date: 20070910 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
CC | Certificate of correction | ||
AS | Assignment |
Owner name: SHARP LABORATORIES OF AMERICA, INC., WASHINGTON Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HSU, SHENG TENG;ZHANG, FENGYAN;REEL/FRAME:028674/0331 Effective date: 20030520 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
AS | Assignment |
Owner name: INTELLECTUAL PROPERTIES I KFT., HUNGARY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SHARP KABUSHIKI KAISHA;REEL/FRAME:029586/0108 Effective date: 20120924 |
|
AS | Assignment |
Owner name: XENOGENIC DEVELOPMENT LIMITED LIABILITY COMPANY, D Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTELLECTUAL PROPERTIES I KFT.;REEL/FRAME:029638/0239 Effective date: 20120926 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553) Year of fee payment: 12 |